Method and apparatus for launching balloons



Aug. 18,1970 w R M N ET AL 3,524,609

METHOD AND APPARATUS 'FOR LAUNCHING BALLOONS Filed Oct. 1, 1968 2Sheets-Sheet 1 i r 1 v:

1 222 /& Xv

. lNVr-fu'rons' FIG I. v JOHN W. SPARKMAN WILLIAM E. HUMPHREY Awemi sAug. 18, 1970 J. w. SPARKMAN' ET L 3, 4,

7 METHOD AND APPARATUS FOR LAUNCHING BALLOONS Filed Oct. 1, 1968 2Sheets-Sheet 2 United States Patent 01 3,524,609 METHOD AND APPARATUSFOR LAUNCHING BALLOONS John W. Sparkman, Boulder, Colo., and William E.Humphrey, Oakland, Calif., assignors to the United States of America asrepresented by the National Science Foundation, Washington, D.C.

Filed Oct. 1, 1968, Ser. No. 764,075 Int. Cl. B64b 1/58, 1/66 US. Cl.244-31 Claims ABSTRACT OF THE DISCLOSURE This invention relates to anapparatus for launching balloons that includes an array of anchor pointsarranged in a substantially circular pattern around a payload at thecenter, a load line connected between the payload and balloon train, abridle consisting of two equal-length cables extending from the point ofattachment of the load line and balloon train downwardly and outwardlyin divergent relation to a pair of the'anchor points on the oppositeside of the payload, and a movable winch capable of circumnavigating thepayload having a mainstay releasably attached to the latter. The methodcomprises using the bridle to keep strain off the load line until justprior to the actual launch, at which point the load is preferablydivided almost equally therebetween, and repositioning the bridle toaccommodate changes in wind direction by moving the winch vehicle toalternately transfer the entire load from one bridle cable to the otherso that each, in turn, becomes slack and can be reconnected at adifferent anchor point.

Thin, strong plastic films have made it possible to conductballoon-borne experiments at altitudes well over 100,000 feet, whichmeans the instrument package lies above all but a fraction of 1% of theearths atmosphere. Balloons for this purpose are quite large, having avolume of several million cubic feet, if they are to lift a heavypayload to these extreme altitudes. The payloads, on the other hand, rungenerally from something a little less than 1000 pounds to as high as10,000 pounds.

Launching a balloon of this type is a difficult and timeconsumingoperation that demands ideal weather conditions and a highly-experiencedlaunch crew. To obviate the necessity for having to cope withunfavorable wind conditions, the preferred launch sites .provide bothcalm weather and natural shelter such as, for example, at the base of ahigh cliff or blufr. Even with these precautions, controlling theballoon in strong gusty winds becomes very difficult and notinfrequently results in damage to the payload. Problems such as this arenot easily solved but, in the meantime, steps need to be taken toprotect the payloads.

Balloon-borne payloads quite generally consist of delicate scientificinstruments that are extremely costly and, therefore, a great deal moreimportant to protect against damage than the balloon train that carriesit aloft which, by comparison, is not worth very much. A payload isparticularly vulnerable during launch because of its close proximity tothe ground. Once airborne, there remains at least some prospect ofparachuting it safely back to the ground; however, while being launched,the payload can be severely damaged and even destroyed as a result of anuncontrollable balloon by being dropped, dragged, bounced or flungagainst some obstacle and, up to the present time, there was little thatcould be done to save it once the launch procedure has commenced.Actually, even a sharp tug on the load line by a rapidly ascendingballoon train might be enough to jar delicate instruments and damagethem so that they will not perform properly thus, oftentimes, causingthe whole experiment to fail.

Wind blowing across the surface of the launch site is, perhaps, thesingle most important environmental factor that one must be able to copewith in order to protect the payload from damage during launch. Thelaunch procedure is a lengthy one requiring that the balloon train belaid out along the ground and a small fraction of its total volumefilled with helium. A main-stay restrains the balloon train and is payedout from a winch until the train is successfully deployed; whereupon,the mainstay is disconnected and the payload is lifted aloft. All duringthis time, an unexpected increase in wind velocity or a change in winddirection can be disastrous to the payload which is already coupledthereto. Even slight damage to the payload means delaying the launchwhile a check is made to see that everything is operating correctly.

It has now been found in accordance with the teaching of the instantinvention that the aforementioned difiiculties can, in large measure, beavoided by isolating the payload from the balloon train by a novelbridle that carries the balloon train tension by itself until just priorto the actual launch, at which time the lift load is distributed betweensaid harness and the load line. If, perchance, a squall or some suchunforeseen condition develops unexpect edly, the load line can beinstantly disconnected from the bridle so that the payload is protectedfrom whatever mishap may befall the balloon train. The balloon train isrestrained and slowly deployed by a movable winch located at theopposite side of the payload from the bridle. A shift in the winddirect-ion can be accommodated by moving the winch vehicle around thecircle so that the anchor line or mainstay places the balloon train inposition to produce slack in one cable of the bridle; whereupon, it canbe removed and fastened to another anchor point in the circular arraythereof while the lift load is carried entirely by the taut one.Reversal of this procedure is used to relocate the other bridle cable sothat, upon completion of the operation. The balloon train is positioneddirectly upwind and the bridle downwind of the payload. The mainstay isdisconnected during erection, preferably at the point where the lift isbeing shared between the bridle anchors and load line and, once the loadis airborne, the bridle can be released.

It is, therefore, the principal object of the present invention toprovide a novel method for launching balloons where the payload isisolated and may even be disconnected from the balloon train until justprior to the actual launch.

A second objective of the invention herein disclosed and claimed is theprovision of a balloon launching apparatus that can quickly and easilybe changed to accommodate a shift in wind direction without disturbingthe payload.

Another object is to provide a launch apparatus of the typeaforementioned that includes a bridle which carries the entire lift loaduntil just prior to launch.

Still another objective is the provision of a circular array of bridleanchor points that cooperates with a vehicle mounted mainstay winch toprovide means for alternately slacking off the bridle cables so thatthey can be relocated in different positions.

A further object is to provide a balloon-launching apparatus and methodof using same that is simple, easy to use, versatile, inexpensive, safe,foolproof, protective of the payload, and productive of a smooth gentlelaunch.

Other objects will -be in part apparent and in part pointed outspecifically hereinafter in connection with the description of thedrawings that follows, and in which:

FIG. 1 is a diagrammatic perspective showing the final stages in theballoon launching sequence of the present invention;

FIG. 2 is a top plan view show-ing in schematic form the first step inthe method used to change the bridle anchor points so as to accommodatea change in wind direction; and,

FIG. 3 is a top plan View like FIG. 2 showing the final step in thereanchoring sequence.

Referring first to FIG. 1 of the drawings for a detailed description ofthe present invention, it will be seen that, in the particular formillustrated, the balloon train, which has been designated broadly byreference numeral 10, is of the dual balloon type that includes both alaunch balloon 12 and a main balloon 14 connected to one another inend-to-end relation by a suitable transfer fitting 16 locatedtherebetween. Also considered a part of the balloon train is the loadline 18 which, in the particular form shown, comprises a yoke-typeharness connected at its apex to the lower end of the main balloon 14and diverging therefrom to points of attachment on opposite sides of thepayload 20. The balloon train could, of course, include only a singlelarge balloon rather than the two shown without materially alteringeither the launch apparatus or method of using same in accordance withthe teaching of the instant invention although, admittedly, thetechniques of filling the balloons may vary with the different types ofballoon trains, but these aspects of the launch sequence are old in theart and form no part thereof.

Using the payload 20 as the center, a plurality of deadmen 22 arearranged in substantially equi-angularly spaced relation therearound toform a circular anchor array that has been indicated in a general way byreference numeral 24. The balloon train 10 is attached to this circularanchor array by a bridle that has been broadly designated by referencenumeral 26 and which comprises a pair of cables 28 and 30 ofsubstantially equal length. These cables diverge from the point ofconnection be tween the main balloon and payload harness downwardly andoutwardly to a circumferentially displaced pair of the deadmen 22 thatlie downwind of the payload.

The inflated launch balloon 12 is gradually allowed to rise, lifting thedeflated main balloon off the ground by paying out an anchor cable orso-called mainstay 32 from a mobile winch 34- which, in the particularform shown, is mounted on the bed of a truck 36 that circles the anchorarray 24 and payload 20 at a considerable radial distance therefrom,although somewhat less than the overall length of the balloon train 10.It is important that the winch 34 be mobile as will appear presently;however, obviously, it need not be mounted on a truck but could, forexample, roll along a monorail or some other type of more permanentinstallation.

Now, the ideal launch condition is that shown in FIG. 1 where theballoon train 10 is deployed directly upwind of the payload 20 and thebridle 26 directly downwind thereof, the wind direction having beenindicated by the arrow. The main balloon 14 is laid out along theground, the mainstay connected to the transfer fitting 16, and thelaunch balloon 12 inflated in the usual manner. All during these stepsin the launch procedure, the bridle 26 is connected to the balloontrain, but there is no need to attach the load line or harness 18 as yetalthough, obviously, it may be so connected if desired.

Next, the winch 34 is actuated to pay out sufficient anchor line ormainstay 32 to loft the launch balloon 12 to an elevation which willraise the main balloon and remaining elements of the balloon train offthe ground, such a condition having been indicated by full lines inFIG. 1. At this point, the actual moment of launch is imminent and thepayload 20 can be connected to the balloon train by means of its harness18, it being most unlikely that any shift in wind direction or abruptincrease in wind velocity will occur during the few minutes remainingbefore the balloon train is out free. Note, however, that with both themainstay 32 and bridle 26 still connected, the payload 20 remainsessentially isolated from the balloon train in case of an emergency. Ifnecessary, the payload harness can yet be disconnected and the balloontrain can be relocated to accommodate a change in wind directionregardless of whether the payload is attached thereto or not.

The next stage in the normal launch procedure is that at which the slackis removed from the payload harness and the first strain is placedthereon, such -a condition having been shown in FIG. 1 by the brokenlines adjacent the full line representation. The relative lengths of theharness and bridle cables are selected such that, as the apex of thelatter moves into position above the payload, the lift load isdistributed or shared therebetween. Actually, the mainstay 32 may bereleased from the transfer fitting 16 at any time after the payloadharness becomes taut indicating that it has begun to share the liftload. Obviously, at this point the payload will not be jerked off theground as would be the case if the mainstay were released while slackremained in the payload harness. Also, with the harness sharing the liftload with the bridle, the payload is ready to be lifted off the ground.Now, as aforementioned, the mainstay can be relaxed at any time afterthe payload harness is carrying part of the lift load; however, testshave shown that the best procedure in terms of reliability andacceptable payload acceleration is to release the mainstay when the liftload is shared approximately equally between the harness and bridle.

The final step in the launch procedure is, of course, to release thebridle from the anchor array. This is done after the mainstay has beendisconnected and at any time after the payload is airborne. Theabove-described launch procedure is smooth and reliable offering maximumprotection to the payload, which remains efiectively isolated from thelaunch system until the final stages of the operation.

Next, with reference to FIGS. 2 and 3, the procedure for reorienting theballoon train to compensate for a. change in wind direction will be setforth in detail. Assume that the original wind direction was radiallyinward toward the payload 20 along the line of the arrow paralleling themain balloon 14 in FIG. 2. Next, assume a slight change in the winddirection to that indicated by the broken line arrows in both FIGS. 2and 3. As the wind changes direction, the launch balloon 12 will bedeflected so as to swing sideways until it occupies a position somethinglike that shown in broken lines in FIG. 2 immediately adjacent the fullline position. When this occurs, the launch crew must relocate thebridle so as to connect it more or less directly downwind of the balloontrain in accordance with the new wind direction.

The first step in relocating the bridle is to move the winch vehicle 36from position A in FIG. 2 clockwise to position B shown in broken lines.In so doing, cable 28 of the bridle 26 becomes slack, while the othercable 30' carries the full lift load. Cable 28, therefore, can bedisconnected from deadman 22a of the anchor array and reconnected todeadman 22b.

From position B in FIG. 2, the winch vehicle moves counterclockwise downto position C shown in full lines in FIG. 3 where cable 30 of the bridlebecomes slack and cable 28 thereof carries the entire lift load. Here,as before, cable 30 is removed from deadman 220 of the anchor array andreconnected at deadman 22d, thus placing the bridle in position suchthat the wind is blowing in a direction essentially bisecting the angleformed between the legs thereof.

The final step in the sequence is to move the winch vehicle 36 toposition D shown in broken lines in FIG. 3 when the balloon train isdirectly upwind of the payload. In actual practice, relocating thebridle in accordance with the above-described procedure'can beaccomplished in less than ten minutes under ordinary circumstances. Notealso, this can be carried out with the payload harness connected to theballoon train so long as the latter remains slack.

In closing, a few general comments concerning the construction andgeometry of the system as above-described would be helpful. First ofall, it should be obvious that one of the essential features of thesystem is a pair of arcuately-adjustable anchor points for the free endsof the bridle so that the legs thereof may be placed on the downwindside of the payload in divergent relation to one another such that theincluded angle therebetween is essentially bisected by a line passingthrough the payload in the direction the wind is blowing. It is notnecessary, therefore, that the anchor ring consist of a plurality ofangularly-spaced anchor points as the same thing could be accomplishedwith a circular rail of some sort carrying rolling anchor blocks thatcould be fastened at various points therealong. The systemabove-described, including the circular array of deadmen, is, of course,considerably less expensive than some elaborate rail system and, whileit does not provide an infinite variety of anchor point locations, thereare generally enough selections available to answer the needs of thelaunch system.

The legs of the bridle are preferably connected on the downwind side ofthe payload which means, of course, that they will be spaced apartangularly less than 180. If connected at opposite diametric points onthe anchor point circle, the length of the load-carrying harness wouldhave to be selected such that it became taut when the apex of the bridlemoved into position directly over the payload; otherwise, it would notbe possible to transfer any of the lift load to the harness beforereleasing the bridle, nor would it be possible to leave the harnessslack until the final stages of the launch. These difliculties areeliminated quite easily by simply connecting both legs of the bridle toanchor points downwind of the load. In so doing, the harness can remainslack until the final stages of the launch; yet, become taut so as toassume a share of the lift load long before the apex of the bridlereaches a position directly over the payload. On the other hand, oncesuch a position is reached, the payload will already be airborne so thatthe bridle can be released from the anchor points without danger of thepayload striking the ground as the balloon swings downwind overhead.

What is claimed is:

1. The apparatus for launching a balloon train of the type including atleast one gas-filled envelope adapted to lift a load suspended from theunderside thereof which comprises: anchoring means located in anessentially circular ring about the load so as to define a plurality ofcircumferentially-spaced anchor points; a V-shaped bridle having theapex thereof connected to the lower end of the balloon train and itslegs extending in divergent relation past the load on opposite sidesthereof to a pair of angularly-displaced anchor points located on thefar side of the latter, said bridle being anchored such that the angleformed by the legs thereof is substantially bisected by a radial linepassing through the load and extending in the direction the wind isblowing, and the length of said bridle being such that the apex thereofcan move upwardly following an arcuate path from a position on the nearside of the payload and clear the latter as it passes overhead; aflexible harness connecting the load to the lower end of the balloontrain and to the bridle at approximately the apex of the latter, saidharness being of a length selected to become taut approximately when theapex of the bridle reaches a position directly above the load; winchmeans movable in an arcuate path outside the anchor point ring on thenear side of the payload;

and, releasable anchor cable means forming a mainstay extending from thewinch means to the gas-filled envelope of the balloon train, saidmainstay and winch means cooperating upon actuation of the latter tocontrol deployment of the balloon train until the lift thereof is sharedby the harness and the load is airborne whereupon said mainstay may bereleased followed by the bridle.

2. The apparatus for launching balloons as set forth in claim 1 inwhich: the legs of the bridle are both of a length greater than theradius of the anchor point circle and approximately equal to oneanother.

3. The apparatus for launching balloons as set forth in claim 1 inwhich: the circle of anchor points and the path of arcuate movement ofthe winch means are substantially concentric about the load as thecenter.

4. The apparatus for launching balloons as set forth in claim 1 inwhich: the legs of the bridle are anchored on the downwind side of thepayload.

5. The apparatus for launching balloons as set forth in claim 1 inwhich: each leg of the bridle is capable. of carrying the entire liftload of the balloon train while the other of said legs is slack.

6. The apparatus for launching balloons as set forth in claim 1 inwhich: the winch means is movable to a position directly upwind of thepayload.

7. The apparatus for launching balloons as set forth in claim 1 inwhich: the maximum overall length of the load and its harness measuredfrom the bottom of the former to the top of the latter when taut isapproximately equal to perpendicular distance from the center of theanchor point circle to the apex of the bridle when the latter isdirectly overhead.

8. The method of launching a balloon carrying a load suspended therefromon a harness which comprises: anchoring the balloon on the downwind sideof the load with a bridle adapted to keep the harness slack until thepoint at which the latter attaches to the balloon reaches an overheadposition relative to the load, controlling the ascent of the balloonfrom a position upwind thereof by paying out a mainstay connectedthereto until it is fully airborne, disconnecting the mainstay from theballoon following transfer of a portion of the lift developed by thelatter from the bridle to the harness, and releasing the bridle afterdisconnecting the mainstay once the load is airborne.

9. In a balloon launching system of the type having several anchorpoints arranged in a ring around the load, a V-shaped bridle having theapex thereof connected to the balloon and its legs diverging to a pairof angularlyspaced anchor points on the downwind side of the load, and amobile winch movable from one position to another on the upwind side ofthe load releasably connected to the balloon by a mainstay, the methodfor relocating the balloon into a position directly upwind of the loadupon a change in wind direction which comprises the steps of: moving thewinch to one side of a line bisecting the angle formed by the legs ofthe bridle so as to introduce slack in the leg on the same side,reconnecting said leg while still slack to a second anchor pointdisplaced from its original anchor point in the same direction and atapproximately the same angle as the new wind direction bears to the oldwind direction, moving the winch back again to the opposite side of theline bisecting the angle formed by the legs of the bridle as originallypositioned so as to introduce slack in its other leg, reconnecting saidother leg to a second anchor point displaced from its original positionin the same direction and through approximately the same angle as thatthrough which the (first leg was moved, and locating the winch at apoint substantially directly upwind of the load.

10. The method of launching a balloon with a load suspended therefrom ona harness which comprises the steps of: anchoring the balloon on thedownwind side of the load so as to essentially isolate same by keepingthe harness slack until said balloon is fully airborne, controlling theascent of the balloon from the upwind side thereof by restraining sameuntil the slack has left the harness and a portion of the lift load istransferred thereto, releasing the restraint on the upwind side when thelift load is shared approximately equally between the harness anddownwind anchor, and disconnecting the downwind anchor after the loadhas become airborne.

References Cited 8 2,954,187 9/1960 Winzen 24431 2,977,069 3/1961 Huchet a1. 244-3l 3,195,839 7/1965 Dietsche 24431 MILTON BUCHLER, PrimaryExaminer S. W. WEINRIEB, Assistant Examiner US. Cl. X.R.

